The Sorcerer's Apprentice
by weezerz2490
Summary: Mai has only recently discovered that Lin, the Chinese onmyouji, taught Naru how to control his powers. But what if Naru wasn't the only one he had been teaching? And since when did Naru have a sister? The more Mai learns about her aloof boss, the more questions she has about his past.
1. Chapter 1

**Author's note:** This will be based mostly on the anime, but I might include some elements from the manga or light novels. It picks up from where the anime left off, and will probably be a LinXOC story.

I own nothing but my OC.

* * *

"English speech"  
"Japanese speech"  
'Thoughts'  
[ | ] Scene transition and/or time lapse  
(...) shift from one separate group's perspective to another within the same ongoing scene.  
**Setting/scene**  
Flashbacks and changes in POVs will be labeled as needed (unless stated otherwise, it will be third person omniscient)  
SOUND EFFECTS WILL BE IN ALL CAPS

* * *

**One afternoon at  
Shibuya Psychic Research**

"Haah…" Mai sighed dejectedly as she let her head drop onto her desk with a thud.

Naru had only just been released from the hospital, and that workaholic already had them back at the office faster than you could say 'Who you gonna call?' Lucky for Mai, she had somehow managed to finish all of the work she had missed while she was on the last case and waiting in the hospital for Naru to recover from the effects of his less than stellar decision to use his PK to destroy that yebisu. However, upon her return, Mai had discovered that there was going to be a math test a couple of days from now, and that was the one subject she had really been struggling to keep up in. She thought she would take advantage of the weekend and lack of business at SPR to study, but the harder she tried, the more confused she became.

'I guess I could always ask Naru to help…' Mai thought tentatively, until she remembered what had happened the last time. 'Never mind. He'd probably just insult my intelligence and explain it in such a complicated way, that I'd feel even more lost than I am now.' She glanced at Lin's closed office door. 'I wonder if Lin-san might…?' she shook her head, sighing in disappointment.

While their relationship as coworkers had started to improve since the Urado case, she didn't think they had quite reached that level yet. Besides, she the stoic assistant had been typing up a storm in there before he had left to pick up some sandwiches for the three of them. She had no idea why since they hadn't had a case since Naru was hospitalized, but whatever Naru had him doing, she knew the stoic onmyouji probably wouldn't appreciate being delayed anymore, since he had seemed reluctant to stop for even the amount of time it would take him to pickup lunch. She probably should have offered to go instead…

"Mai, Tea!" Naru called a little sharper than usual from within his office.

"Coming." Mai called out in reply as she stood up and headed into the office's kitchenette to prepare his precious tea, chagrined. Naru had been in a bad mood ever since he woke up in the hospital, and it really hadn't helped that business had been so slow lately. She hoped they would get a new client soon so Naru could remove that stick that was shoved up his—

Mai froze when she heard the bell on the door jingle, signaling that someone had actually entered. Daring to hope, Mai rushed out to greet whoever it was, praying for the sake of everyone involved that it really was a new client and not one of the SPR irregulars showing up to check in on them. Naru might actually _explode_ if it turned out they had just come to socialize. She had to hold in a cry of joy when she saw that the person standing in the middle of the reception area was, indeed, a complete and total stranger. Finally, her prayers had been answered! Thank Kami-sama!

"Excuse me. Is there something we can help you with?" Mai asked politely, smiling brightly at the pretty young woman before her.

She couldn't quite put her finger on it, but the more she looked at her, the more Mai felt that there was something familiar about this new client… She had beautiful, silky hair that cascaded down her back like a black waterfall, while framing her fair face with stylish layers that were sophisticated and sassy at the same time. Her skin was smooth and flawless except for the small beauty mark by her left eye… Her eyes! Mai could feel her own cinnamon brown eyes widen in surprise as she suddenly realized why she looked so familiar. Her eyes were the same deep blue, indigo color as Naru's! The only difference was that this woman's eyes seemed to be a little lighter and seemed to sparkle with amusement as she watched the younger girl gape at her in shock, but Mai couldn't help it—after all, this woman was practically a female Naru!

"Um, are you alright?" the female Naru asked, caught between concern and amusement over Mai's priceless expression.

Mai snapped herself out of it by shaking her head to clear the distracting thoughts away.

"Y-Yes! I'm sorry, it's just that you look a lot like someone I know…" Mai apologized a little nervously as she rubbed the back of her neck sheepishly, hoping her strange behavior wouldn't scare her away.

"That's alright, I get that a lot." Naru's female doppelganger replied carelessly, smiling kindly at Mai as she shrugged it off. "You're Taniyama-san, right? Would you mind getting 'Shibuya Kazuya' out here for me?" She asked sweetly.

Mai nodded dumbly, stunned by how similar her smiling face was to 'Dream Naru's', and went to fetch said narcissist before she could make an even bigger fool of herself.

She paused mid-step when something occurred to her.

'Wait… how did she know my name? I don't remember telling her…' Mai realized, confused. She froze when she realized that fetching her boss was no longer necessary. Naru was already coming to her, and he didn't look pleased.

"Mai, how long are you planning to make me wait for my te—" Naru started to ask when he was rather rudely interrupted.

"—Hey! Long time, no see… _Naru_." The woman said, smiling like a Cheshire cat when he came into view.

The unflappable narcissist froze. Even though Naru's poker face was still firmly in place, he was extremely surprised to see who their visitor was.

"Mei… What are _you_ doing here?" Naru asked calmly, furrowing his brow slightly. "Shouldn't you still be in Africa?"

'Africa_!_?' Mai thought incredulously, glancing rapidly between the two of them. Just how did these two know each other, and what could she have possibly been doing in _Africa_, of all places_!_?

The woman, Mei, clicked her tongue in disappointment.

"Your loving older sister came all the way here for a visit because she and your parents were worried sick about you, and _that's_ your reaction?" Mei asked him, looking extremely unimpressed. "Where's my hello? Aren't you glad to see me?"

"Thrilled. I'm so excited I can barely contain myself." Naru deadpanned, looking anything but.

"E-Eh…? Naru's onee-san_!_?" Mai asked, stunned. It certainly would explain why they looked so alike, but for some reason… she just couldn't imagine Naru having a sister.

"Yep." Mei said sunnily as she turned back to Mai, ignoring Naru's unenthusiastic reply, too used to it to let something so minor bother her. "I'm Shibuya Mei, Naru's older sister… But, judging by your reaction, I guess he hasn't mentioned me…" She said, raising an eyebrow at her younger brother as she gave him a look. "… But you can just call me 'Mei'. My brother's a little antisocial and has a sharp tongue, but please continue being friends with him anyway." Mei told Mai, smiling kindly as she bowed politely to the younger girl.

"Ah, of course! Please, call me Mai!" Mai replied a little nervously as she quickly returned her bow. She was a little caught off guard by this sudden revelation, but Naru's sister seemed to be pretty nice and polite. '_So different from a certain someone…'_ Mai thought, sweat dropping as she glanced at her boss out the corner of her eye.

"Anyway, _Naru_…" Mei said a little patronizingly as she turned back to her brother, finally ready to explain the details of her visit. "Since even _Lin_ is having trouble keeping you in check, your extremely worried and concerned parents decided to send your lovely sister in as back-up." She said loftily, smirking slightly at the dissatisfied glare Naru was giving her. After giving them all such a scare, she was more than happy to hassle him a little for revenge. Hopefully, having to suffer some mild form of embarrassment would make their favorite narcissist think twice about trying to pull a stunt like _that_ again.

"That is completely unnecessary. I don't need you to babysit me. Stop treating me like a child." Naru said coldly, clearly against the idea. It was a sting to his pride to have to have not only a bodyguard, but now a babysitter as well. He knew he messed up, and he had no intention of making the same mistake twice. Why couldn't they just leave well enough alone?

"It's cute how you think you have a choice, Naru. Did you forget that you're still a minor, and therefore, still subject to your parents' authority as your legal guardians? Didn't think so. I'll stop treating you like a child when you stop acting like one." Mei stated calmly, completely unfazed by his glare. "I mean, do you seriosly think that _selfishly_ using powers you that you _know_ can _seriously harm_ you just because of your wounded pride, and making _everyone _who cares for you _worried_ and _scared _because you _nearly died_, are the actions of a _responsible adult_? If so, then think again. You should consider yourself lucky that I'm here only here to stay with you and not to drag your sorry behind back home." She stated bluntly, emphasizing certain words to make sure he got the point.

Her little brother might be a genius, but he could be pretty thick about some things. Naru just stared back at her in silence, chagrined, because he knew any attempt to justify his actions would just land him in more hot water with Mei, and then she'd never shut up. There was also very little he could say on the matter without revealing just how illogical he had been acting at the time, which was not something he would care to admit, especially in front of Mai. In his opinion, she had already seen enough of this little family circus.

Mai didn't really mind watching the two siblings interact since it was letting her see another side of her normally cool and stoic boss. He actually seemed to be sulking! She was happy to have been able to learn something new about him. Mai had actually started to feel a little concerned when she realized that no one from Naru's real family had shown up to check on him, so she was relieved to know someone really had cared enough to come for him… but she seriously never would have guessed that Naru had an older sister, especially such a social and cheerful one like Mei… Although, Mai had to admit that she found it kind of funny that they both sounded so similar with their sharp tongues and blunt insults when scolding people. Mai smirked slightly. It was kind of nice to see Naru get a taste of his own medicine for once, and while Mai had blamed herself for provoking him before, she had come to accept that it wasn't entirely her fault, so she was glad Mei was there to give Naru a proper scolding for them. She had a feeling Naru might actually be more likely to listen for once if it came from his older sister.

"Fine." Naru finally said grudgingly after weighing his options. Letting Mei stay with him in Japan and working together at SPR was definitely the lesser of two evils. He couldn't return home. Not yet. "But you'll be working under Lin as his assistant." He added. It was probably Lin's fault she had come in the first place, since he probably reported everything that had happened on the last case to his parents. He should have expected something like this, knowing what a worrywart his mother could be.

As though summoned by Naru's words, the tall Chinese man returned to the office no sooner than the words had left his mouth.

Lin blinked in surprise when he saw Mei standing in the middle of the room with Naru and Mai. Apparently, he hadn't been expecting her to come either…

"Hello, Lin. Hóunoih móuhgin." Mei said, smiling happily as she took full advantage of Lin's hands being full, and hugged him.

Mai gaped at her, positively stunned. _How brave_... to think that there was actually someone who would _dare_ to purposefully invade _that_ Lin-san's personal space… Mai was certain Mei was about to be on the receiving end of one of Lin's chilling glares, however, instead of pushing Mei away, the normally stoic man's lips curled up into a slight smile, and his piercing, dark eyes softened as he gazed down at the woman who barely came up to his chest, even in heels. Consider Mai's brain imploded.

"Yes, it's good to see you again, Mei." Lin said. Mei grinned happily as she released him so he could set the bags of food down. She turned back to Naru with a triumphant gleam in her eye.

"Well, it's nice to see that _someone_ missed me!" She huffed in feigned annoyance at him. Naru just turned his head, refusing to look at her. "Aw, are you sulking because I went straight into lecturing mode without giving you a hug?" Mei teased as she threw her arms around her brother, practically glomping him.

"_Get off."_ Naru said bluntly, clearly chagrined, as his aura started to darken. Why must his older sister insist on acting as though her sole mission in life were to embarrass him? It was hard to believe they were really related sometimes.

Mai sweat dropped as she watched Naru struggle to break free from her vice-like grip. Naru almost seemed normal when he was interacting with Mei… Almost.

"Um, Lin-san… what language was that Mei-san spoke earlier when she greeted you?" Mai asked curiously, deciding not to get involved with the siblings' roughhousing. "Was that Chinese?"

Lin nodded.

"She was greeting me in Cantonese. Cantonese is the main dialect used in Hong Kong." He explained.

"Hmm, Naru's Onee-san seems pretty amazing…" Mai said thoughtfully. Was everyone in the Shibuya family so ridiculously smart and good-looking?

"Would you at least make an effort to _pretend_ to be normal while at the office?" Naru asked once he had finally managed to regain his freedom. His voice was dripping with disdain and sarcasm. "As your 'boss', I shall be expecting you to behave professionally from now on." Naru stated coldly as he grabbed his sandwich and retreated to his office.

Mai flinched slightly when he slammed the door shut. She glanced cautiously at Mei, hoping Naru hadn't hurt her feelings. Mei was trembling…

Trembling from the effort of holding in her laughter as she held a hand over her mouth. Mai sweat dropped. Okay, so maybe Mei _was_ a little strange…

"Pfft! Haha… sorry, sorry!" Mei apologized, keeping her voice down so Naru wouldn't hear her and get even more ticked off. "I just couldn't resist teasing him after not seeing him for so long, and I figured it was the least I could do for paying him back after giving us all such a scare." She explained, smiling wryly at the puzzled expression on Mai's face. Lin let out a quiet chuckle as well. It had been a while since he had been able to watch Mei ruffle Naru's feathers like that.

"So, it appears you'll be my assistant from now on. Follow me, and I'll explain everything." Lin told Mei as he grabbed his own lunch and led her into his office.

"…" Mai said as she stared after them, blinking. She wasn't sure she really understood everything that had just happened, but one thing was for sure.

Things just got a whole lot more interesting at SPR…

"Mai, tea!"


	2. Chapter 2

I own nothing but my OC.

* * *

"English speech"  
"Japanese speech"  
'Thoughts'  
[ | ] Scene transition and/or time lapse  
(...) shift from one separate group's perspective to another within the same ongoing scene.  
**Setting/scene**  
Flashbacks and changes in POVs will be labeled as needed (unless stated otherwise, it will be third person omniscient)  
SOUND EFFECTS WILL BE IN ALL CAPS

* * *

_**Ghost In The Stacks: Part I**  
_

* * *

"I must admit, I'm a little surprised you agreed to play babysitter." Lin said once he and Mei were safely inside his office with the door closed.

"Well, I'll admit that I'm a little peeved that I had to rush to finish my photo shoot in Africa for _National Geographic_ early, but even if I hadn't been asked to, I still would've come to check on Noll. We might've ended up being adopted into different families, he's still my baby brother." Mei said, smiling wryly as she shrugged. "Besides, did you forget that I had originally tried to come along with you guys from the very beginning? If I hadn't been outvoted by all of you and already set up to go on that shoot, I'd have already been here." She reminded him. "It's been a while since I've done any ghost hunting." She grinned impishly. Even if she was primarily a photographer by trade, she still liked to help out with the 'family business' every now and then.

Lin smiled wryly as he sighed and shook his head at her, almost like a parent indulging one of their child's silly whims.

"Then, let's hope you haven't gotten too rusty. As my assistant, you'll need to be able to keep up with me, after all." He teased slyly, smirking ever so slightly at the faint blush forming on her cheeks as she pouted, taking exception to the implication that she might have slacked off on her training, but she quickly recovered. Mei returned Lin's smirk as she spoke.

"Who knows? Maybe I'll surprise you."

[ | ]

**The following afternoon,  
At the office  
**

"Argh!" Mai growled in frustration as she ruffled her hair. Math truly, _deeply_ sucked_!_! Why did it have to be so hard_!_? Today at school, Mai had learned that she wasn't the only one having trouble understanding the latest chapter, which made her feel a little bit better, until she realized that pretty no one knew enough to help her understand it better.

"Are you alright, Mai-chan?" Mei asked, a little concerned to see her new coworker so frustrated that the girl looked like she was about ready to pull her own hair out.

"Ah, yeah… I just _really_ hate math." Mai said, chagrined. She glanced over at Mei a little sheepishly. She had been so focused on her homework, that Mai had almost forgotten she wasn't the only one with a desk in that room anymore.

Since it had been decided that Mei would not only act as Lin's assistant but also as Mai's substitute during school hours, they had set her desk up in the reception area, too. However, unlike Mai, who wasn't allowed to use the phone except to call the SPR irregulars whenever they had a case, Mei had been allowed to actually receive the phone calls and speak to the caller instead of automatically transferring it to either Lin or Naru. Mai had been a little miffed about that, but whatever. It wasn't that big of a deal, and even though she was new to the office, Mai could tell Mei had more experience with working at a place like SPR from how efficient she was, and she was twenty-two years-old already (even though she looked a little younger), so it was understandable that they would rely on her more…

"… Mai?" Mei called, snapping her out of her thoughts.

"Ah! Sorry, I just zoned out for a bit there…" Mai said, smiling wryly as she laughed a little nervously. "Where you trying to say something before?"

"Yes, I was wondering if you'd like some help?" Mei offered kindly, smiling wryly at Mai's silliness. She couldn't help but like the spunky high school girl. As far as she was concerned, anyone who could come up with an ingenious nickname like 'Naru the Narcissist' for her idiot scientist brother and get away with it, was all right in her book.

"R-Really_!_?" Mai shouted excitedly, nearly jumping of her chair for joy. Her eyes were sparkling with hope of salvation from the hell known as high school math.

"Really. I feel your pain, Mai. I've always disliked math with great intensity, too. I've even been tempted to burn the my textbook once or twice." Mei said, nodding sympathetically. "I'm not too bad at it, though, so maybe I can help you figure some of these problems out if I remember enough of it."

"Mei-sama~!" Mai cried in delight as she hugged the older girl with tears of joy and relief streaming down her face. Now she wouldn't have to fail!

"Haha, alright, alright… calm down, Mai-chan." Mei said, smiling wryly, as she laughed good-naturedly at Mai's antics.

_JINGLE~_

Both of them looked up as the bell on the door rang, and their latest client walked in. The man was a little on the short side for a man, and he appeared to be in his mid-thirties. He seemed a little hesitant to enter, as he remained standing in the doorway, rather than taking a seat or introducing himself.

"Ah, welcome!" Mai greeted him cheerfully, still elated by the promise of help with the dreaded math. "Please, come in."

"Um… good afternoon…" He greeted them a little nervously. "You are… what one would call 'mediums'… right?" He asked Mai and Mei. The two girls glanced at each other.

"Well, I suppose you could say that. I'm Shibuya Mei. Why don't you have a seat…?" Mei said soothingly, silently asking for his name.

"Oh, um… Yamada. I'm Yamada Akio." He said a little less timidly as he sat down on one of the leather couches.

"Mai, please make some tea while we discuss Yamada-san's case." Mei said politely, smiling reassuringly at Yamada-san, as she took a seat across from him.

"Okay." Mai said cheerfully as she headed off to the kitchenette. It was nice to have some around here who actually bothered to say 'please' and 'thank you.'

"So, what seems to be the problem, Yamada-san?" Mei asked.

"Oh, well... I'm not really a superstitious person, but lately some of the younger volunteers at the Library I work at have refused to come because they claim it's being haunted. They're good kids, so I know they aren't trying to pull some kind of malicious prank on me, but the more these rumors spread, the more people start to avoid the place. Everyone I've talked to who's supposed to have seen the ghost all described her as a young, foreign woman with red hair and startling green eyes. She seemed harmless enough, since the spookiest thing about her was that she would disappear if they got too close. I haven't seen this 'ghost' for myself, but lately books have started falling off the shelves even though no one is anywhere close to them, and doors will randomly open and close on their own." Yamada explained.

"Which library do you work at, Yamada-san?" Mei asked curiously.

"Oh, I work at the small public library that just reopened in Yoyogi Sanchōme, Hanamaru Library." He replied as Mai rejoined them and served the tea. "It's just a small, neighborhood library, with only a first floor, but it's a pleasant place to relax, at least it was…"

Mai frowned slightly in concern for the man. He looked tired and defeated.

"Reopened? Why was it closed?" Mei asked, wondering if it might have something to do with the ghost (if there was one).

"Well, I think I remember hearing something about an accident that happened there a few years back, when a librarian was crushed by one of the book stacks, but the official reason was because of subsidence. The building was sinking, so they closed it because it was in danger of having its foundation compromised." He said thoughtfully, wracking his brain for the answers.

"Do you think maybe subsidence could have caused the books to slide off the shelves?" Mai suggested. After all, she had seen first hand what kind of crazy things could happen from something like that on her first case in the old school house, but Yamada shook his head.

"No. I don't see how it could, since the ground beneath the building has stabilized. That's why they let us reopen the library, because it stopped. The building's been surveyed and had some renovations done to make it safe again." He explained patiently. "I even checked that myself by placing a marble in the middle of the floor to see if it rolled in ay particular direction because the floor was slanted, but it just sat there, so I know that floor is perfectly flat and level."

"I see… That is rather strange, then." Mei said thoughtfully. "Alright, Yamada-san. We'll take your case, but we'll need a room to use for our base and some place for us to sleep while we keep watch overnight, if possible. We would also appreciate it if you could arrange for us to be able to speak to anyone who is willing to talk about their encounter with the ghost or who have experienced anything else out of the ordinary to help with our investigation."

"Yes, I think that can be arranged. Thank you very much, Shibuya-san." Yamada said, breathing a sigh of relief, as he bowed to them.

"No, thank _you_ for coming to us, Yamada-san. Would you mind giving us your phone number so that we can let you know when to expect us, once we have finished informing our manager?" Mei asked politely, handing him her pen and paper.

"Ah, yes, of course." He said, smiling, as he jotted down his number. The employees here were a little young, but they seemed reliable enough—not at all like the shady and crazy paranormal otaku he had been afraid they might turn out to be.

"Thank you. Take care, Yamada-san." Mei told the older man as she and Mai saw him to the door.

"Goodbye, Yamada-san!" Mai called after him as he left, waving. Once he was gone, Mai turned back to Mei, biting her lip a little nervously when what they had just done sank in. "Um, Mei-san… Not that I'm complaining, but was it really okay for you to accept Yamada-san's case without asking Naru about it first?" She asked cautiously.

"Don't worry. It'll be fine, Mai-chan." Mei said carelessly, waving off her worries. "Whether Naru thinks it's interesting or not, investigating a minor case like this is just what the doctor ordered! It's close by, and it doesn't seem to be too dangerous, so it'll be a good warm-up to help him ease back into the swing of things. He only just got out of the hospital, after all. But, just to be safe… maybe you should duck for cover while I go break the news." She said, smiling wryly.


End file.
